Kelly, Nellie, b 22 Dec 1927; d Feb 1977; last residence Dallas, Dallas Co, TX; SS card issued in TX.
TX Dth Idx, note different spelling for surname:
Kelley, Nellie B., d 15 Feb 1977, Dallas Co, TX.
I would look for an obituary for her, it might tell enough to prove whether she is "your" Nellie.Also, an obit should list survivors, and you could tell if she had any children.
Too bad you don't know her husband's given name.Using online directory http://wwwswitchboard.comhttp://wwwswitchboard.com there is an N.C. Kelley in Amarillo.If Nellie is a widow she might be listed by her initial, women often do that.